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Barros LNLC, de Araujo RN, do Nascimento EP, Gama AJDA, Neves GA, Torres MAM, Menezes RR. Influence of Fast Drying on the Morphology of α-Fe 2O 3 and FeMnO 3/α-Fe 2O 3 Fibers Produced by Solution Blow Spinning. Nanomaterials (Basel) 2024; 14:304. [PMID: 38334575 PMCID: PMC10857625 DOI: 10.3390/nano14030304] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2023] [Revised: 01/19/2024] [Accepted: 01/24/2024] [Indexed: 02/10/2024]
Abstract
α-Fe2O3 and FeMnO3/α-Fe2O3 fibers were successfully prepared via Solution Blow Spinning (SBS). The effect of drying during the SBS process on fiber morphology was evaluated by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and N2 adsorption-desorption isotherms. A slow drying promoted continuous fibers with rough surfaces and lower average diameters. However, fast drying enabled the production of fibers with low densification and many surface pores with higher BET-specific surface areas. The porous fibers produced have potential applications in energy generation and storage.
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Affiliation(s)
- Lara Nágela Lopes Cavalcante Barros
- Graduate Program in Materials Science and Engineering, Federal University of Campina Grande, Campina Grande 58429-900, Brazil; (L.N.L.C.B.); (E.P.d.N.)
| | - Rondinele Nunes de Araujo
- Laboratory of Materials Technology, Federal University of Campina Grande, Campina Grande 58840-000, Brazil; (A.J.d.A.G.); (G.A.N.)
| | - Emanuel Pereira do Nascimento
- Graduate Program in Materials Science and Engineering, Federal University of Campina Grande, Campina Grande 58429-900, Brazil; (L.N.L.C.B.); (E.P.d.N.)
| | - Alexandre José de Almeida Gama
- Laboratory of Materials Technology, Federal University of Campina Grande, Campina Grande 58840-000, Brazil; (A.J.d.A.G.); (G.A.N.)
| | - Gelmires Araújo Neves
- Laboratory of Materials Technology, Federal University of Campina Grande, Campina Grande 58840-000, Brazil; (A.J.d.A.G.); (G.A.N.)
| | - Marco Antonio Morales Torres
- Department of Theoretical and Experimental Physics, Federal University of Rio Grande Do Norte, Natal 59078-970, Brazil;
| | - Romualdo Rodrigues Menezes
- Laboratory of Materials Technology, Federal University of Campina Grande, Campina Grande 58840-000, Brazil; (A.J.d.A.G.); (G.A.N.)
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de Brito AS, Valerio-Cuadros MI, Silva Tupan LF, Oliveira AA, Barco R, Ivashita FF, Passamani EC, Humberto de Araújo J, Morales Torres MA, Paesano A. Magnetic properties of Fe-doped NiO nanoparticles. Heliyon 2023; 9:e22876. [PMID: 38144307 PMCID: PMC10746408 DOI: 10.1016/j.heliyon.2023.e22876] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Revised: 10/16/2023] [Accepted: 11/22/2023] [Indexed: 12/26/2023] Open
Abstract
Undoped and Fe-doped NiO nanoparticles were successfully synthesized using a lyophilization method and systematically characterized through magnetization techniques over a wide temperature range, with varying intensity and frequency of the applied magnetic fields. The Ni1-xFexO nanoparticles can be described by a core-shell model, which reveals that Fe doping enhances exchange interactions in correlation with nanoparticle size reduction. The nanoparticles exhibit a superparamagnetic blocking transition, primarily attributed to their cores, at temperatures ranging from above room temperature to low temperatures, depending on the Fe-doping level and sample synthesis temperature. The nanoparticle shells also exhibit a transition at low temperatures, in this case to a cluster-glass-like state, caused by the dipolar magnetic interactions between the net magnetic moments of the clusters. Their freezing temperature shifts to higher temperatures as the Fe-doping level increases. The existence of an exchange bias interaction was observed, thus validating the core-shell model proposed.
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Affiliation(s)
- Alex Soares de Brito
- Departamento de Física, Universidade Estadual de Maringá, Av. Colombo, 5790, Jardim Universitário, 87020-900, Maringá, PR, Brazil
| | - Marlon Ivan Valerio-Cuadros
- Departamento de Física, Universidade Estadual de Maringá, Av. Colombo, 5790, Jardim Universitário, 87020-900, Maringá, PR, Brazil
- Facultad de Ciencias Físicas, Universidad Nacional Mayor de San Marcos, Lima, Peru
| | - Lilian Felipe Silva Tupan
- Departamento de Física, Universidade Estadual de Maringá, Av. Colombo, 5790, Jardim Universitário, 87020-900, Maringá, PR, Brazil
- Centro Universitário Ingá, 87035-510, Maringá, PR, Brazil
| | - Aline Alves Oliveira
- Departamento de Física, Universidade Estadual de Maringá, Av. Colombo, 5790, Jardim Universitário, 87020-900, Maringá, PR, Brazil
| | - Reginaldo Barco
- Departamento de Física, Universidade Estadual de Maringá, Av. Colombo, 5790, Jardim Universitário, 87020-900, Maringá, PR, Brazil
| | - Flávio Francisco Ivashita
- Departamento de Física, Universidade Estadual de Maringá, Av. Colombo, 5790, Jardim Universitário, 87020-900, Maringá, PR, Brazil
| | - Edson Caetano Passamani
- Departamento de Física, Universidade Federal do Espírito Santo, 29075-910, Vitória, ES, Brazil
| | - José Humberto de Araújo
- Departamento de Física Teórica e Experimental, Universidade Federal do Rio Grande do Norte, 59078-970, Natal, RN, Brazil
| | - Marco Antonio Morales Torres
- Departamento de Física Teórica e Experimental, Universidade Federal do Rio Grande do Norte, 59078-970, Natal, RN, Brazil
| | - Andrea Paesano
- Departamento de Física, Universidade Estadual de Maringá, Av. Colombo, 5790, Jardim Universitário, 87020-900, Maringá, PR, Brazil
- Departamento de Física Teórica e Experimental, Universidade Federal do Rio Grande do Norte, 59078-970, Natal, RN, Brazil
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Barbosa FF, Tavares JE, Albuquerque ADR, Morales Torres MA, Rodríguez-Castellón E, Pergher SBC, Braga TP. Catalytic dehydration of glycerol over Cu-Fe-Al-based oxides: understanding changes in active sites throughout the reaction. RSC Adv 2023; 13:31182-31200. [PMID: 37881763 PMCID: PMC10594406 DOI: 10.1039/d3ra05454c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Accepted: 10/18/2023] [Indexed: 10/27/2023] Open
Abstract
The glycerol conversion into acetol using Fe, Al and Cu-based oxides was investigated. XRD results indicate the formation of nanosized particles with high phase dispersion, however, Raman, Mössbauer, 27Al NMR and XPS spectroscopies suggest the presence of iron(iii) oxide, Al2O3 and CuO phases. The FTIR with pyridine adsorption revealed high Lewis acidity. The TPR profile showed the reduction temperature range for the Fe3+ and Cu2+ sites, indicating the suitable condition for pretreatment. The N2 adsorption-desorption isotherms indicated the presence of micro-mesopores with interesting textural properties and specific area varying between 71 and 220 m2 g-1, while the porous morphology was observed by SEM and TEM images. The optimized catalytic tests showed glycerol conversion of 60% and acetol selectivity of 92% with 17% of coke according to TG profile. The recycling tests confirmed the efficiency of the solid, reaching 28% conversion and 91% acetol selectivity after four reuses and, after reactivation in an oxidizing atmosphere, the catalytic performance obtained results close to the second reuse. The interaction between the different Lewis acid sites involved in the mechanisms for the acetol and coke formation on the catalyst surface is discussed. The charge distribution represented by colors which indicates the acid-base surface was evaluated by a simple theoretical-computational study based on the DFT approach. The synergy between the active sites indicates that the presence of Cu0/Cu+ drastically increases the acetol selectivity which is a more important characteristic than the high Lewis acidity of Fen+ and Al3+.
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Affiliation(s)
- Felipe Fernandes Barbosa
- Laboratório de Peneiras Moleculares, Instituto de Química, Universidade Federal do Rio Grande do Norte 59078-970 Natal RN Brazil +55-84-3342-2323
| | - João Edson Tavares
- Instituto de Química, Universidade Federal do Rio Grande do Norte 59078-970 Natal RN Brazil
| | | | | | - Enrique Rodríguez-Castellón
- Departamento de Química Inorgánica, Cristalografía y Mineralogía, Facultad de Ciencias, Universidad de Málaga 29071 Málaga Spain
| | - Sibele B C Pergher
- Laboratório de Peneiras Moleculares, Instituto de Química, Universidade Federal do Rio Grande do Norte 59078-970 Natal RN Brazil +55-84-3342-2323
| | - Tiago Pinheiro Braga
- Laboratório de Peneiras Moleculares, Instituto de Química, Universidade Federal do Rio Grande do Norte 59078-970 Natal RN Brazil +55-84-3342-2323
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Soares JDO, Cavalcanti WEC, Torres MAM, Pergher SBC, De Oliveira FJVE, Braga TP. Synthesis, Characterization and Photocatalytic Activity of CoFe 2O 4/Fe 2O 3 Dispersed in Mesoporous KIT-6. Nanomaterials (Basel) 2022; 12:3566. [PMID: 36296757 PMCID: PMC9611405 DOI: 10.3390/nano12203566] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Revised: 10/03/2022] [Accepted: 10/06/2022] [Indexed: 06/16/2023]
Abstract
The present work aimed to synthesize and characterize a solid based on CoFe2O4/Fe2O3-KIT-6 and evaluate its performance in the photocatalytic degradation of the remazol red ultra RGB dye. By analyzing XRD, N2 physisorption, and Mössbauer results, it was possible to identify that the desired CoFe2O4/Fe2O3 phase was achieved, which maintained its structural properties. The FTIR-pyridine indicated the presence of Lewis acid sites, while TPD-CO2 showed a large amount of weak basic sites. The band-gap energy indicated that the compound can be applied in photocatalytic degradation under UV/visible light, with the possibility of magnetic separation at the end of the reaction. The photocatalysis results indicated that there was complete degradation of the remazol red ultra RGB dye within 1 h of reaction. Despite the absence of H2O2, the combination of the proposed photocatalyst with the anatase phase (TiO2) showed significant improvements in the degradation process. The proposed mechanism for complete dye degradation indicated that a sequence of radical reactions is necessary, generating oxidant species such as •OH and the final products were CO2 and H2O.
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Affiliation(s)
- Johnatan de Oliveira Soares
- Instituto de Química Laboratório de Peneiras Moleculares (LABPEMOL), Instituto de Química, Universidade Federal do Rio Grande do Norte, Natal 59078-970, RN, Brazil
| | - Wesley Eulálio Cabral Cavalcanti
- Instituto de Química Laboratório de Peneiras Moleculares (LABPEMOL), Instituto de Química, Universidade Federal do Rio Grande do Norte, Natal 59078-970, RN, Brazil
| | - Marco Antonio Morales Torres
- Departamento de Física Teórica e Experimental, Universidade Federal do Rio Grande do Norte, Natal 59078-970, RN, Brazil
| | - Sibele Berenice Castella Pergher
- Instituto de Química Laboratório de Peneiras Moleculares (LABPEMOL), Instituto de Química, Universidade Federal do Rio Grande do Norte, Natal 59078-970, RN, Brazil
| | - Fernando José Volpi Eusébio De Oliveira
- Instituto de Química Laboratório de Peneiras Moleculares (LABPEMOL), Instituto de Química, Universidade Federal do Rio Grande do Norte, Natal 59078-970, RN, Brazil
| | - Tiago Pinheiro Braga
- Instituto de Química Laboratório de Peneiras Moleculares (LABPEMOL), Instituto de Química, Universidade Federal do Rio Grande do Norte, Natal 59078-970, RN, Brazil
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da Costa Borges Soares M, Barbosa FF, Torres MAM, Valentini A, dos Reis Albuquerque A, Sambrano JR, Pergher SBC, Essayem N, Braga TP. Oxidative dehydrogenation of ethylbenzene to styrene over the CoFe2O4–MCM-41 catalyst: preferential adsorption on the O2−Fe3+O2− sites located at octahedral positions. Catal Sci Technol 2019. [DOI: 10.1039/c9cy00618d] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The present study describes the catalytic performance of cobalt ferrite supported on MCM-41 for the oxidative dehydrogenation of ethylbenzene.
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Affiliation(s)
- Moisés da Costa Borges Soares
- Laboratório de Peneiras Moleculares (LABPEMOL)
- Instituto de Química
- Universidade Federal do Rio Grande do Norte
- Natal
- Brazil
| | - Felipe Fernandes Barbosa
- Laboratório de Peneiras Moleculares (LABPEMOL)
- Instituto de Química
- Universidade Federal do Rio Grande do Norte
- Natal
- Brazil
| | | | - Antoninho Valentini
- Langmuir - Laboratório de Adsorção e Catálise
- Departamento de Química Analítica e Físico-Química
- Universidade Federal do Ceará
- Fortaleza
- Brazil
| | | | - Julio Ricardo Sambrano
- Grupo de Modelagem e Simulação Molecular
- INCTMN-UNESP
- São Paulo State University
- Bauru
- Brazil
| | - Sibele B. C. Pergher
- Laboratório de Peneiras Moleculares (LABPEMOL)
- Instituto de Química
- Universidade Federal do Rio Grande do Norte
- Natal
- Brazil
| | - Nadine Essayem
- Institut de recherches sur la catalyse et l'environnement
- 69626 Villeurbanne Cedex
- France
| | - Tiago Pinheiro Braga
- Laboratório de Peneiras Moleculares (LABPEMOL)
- Instituto de Química
- Universidade Federal do Rio Grande do Norte
- Natal
- Brazil
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Magno de Lima Alves T, Amorim BF, Morales Torres MA, Bezerra CG, Nóbrega de Medeiros S, Gastelois PL, Fernandez Outon LE, Augusto de Almeida Macedo W. Wasp-waisted behavior in magnetic hysteresis curves of CoFe2O4 nanopowder at a low temperature: experimental evidence and theoretical approach. RSC Adv 2017. [DOI: 10.1039/c6ra28727a] [Citation(s) in RCA: 62] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
We theoretically and experimentally investigated wasp-waisted magnetic hysteresis curves at a low temperature for CoFe2O4 nanopowders.
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Affiliation(s)
- Tibério Magno de Lima Alves
- Instituto Federal de Educação Ciência e Tecnologia do Rio Grande do Norte
- 59015-000 Natal
- Brazil
- Departamento de Física Teórica e Experimental
- Universidade Federal do Rio Grande do Norte
| | - Bruno Ferreira Amorim
- Departamento de Física Teórica e Experimental
- Universidade Federal do Rio Grande do Norte
- 59078-900 Natal
- Brazil
| | | | - Claudionor Gomes Bezerra
- Departamento de Física Teórica e Experimental
- Universidade Federal do Rio Grande do Norte
- 59078-900 Natal
- Brazil
| | - Suzana Nóbrega de Medeiros
- Departamento de Física Teórica e Experimental
- Universidade Federal do Rio Grande do Norte
- 59078-900 Natal
- Brazil
| | - Pedro Lana Gastelois
- Laboratório de Física Aplicada
- Centro de Desenvolvimento da Tecnologia Nuclear
- CDTN
- 31970-201 Belo Horizonte
- Brazil
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